Thomassen disclosed a rotatably mounted display means in his Italian Patent No. 554559 comprising a metal plate 10, two side walls 11 perpendicularly and oppositely mounted on the plate 10, and a frame 16 for rotatably mounting the plate 10 on the frame 16 about an axis 17. However, such a rotatable display when inferentially used for a roadway sign, may have the following drawbacks:
1. If the axis 17 for rotating the plate 10 is vertically erected as shown in FIG. 1 of its Italian Patent disclosure, the plate 10 may not be precisely oriented to present a fully circular shape if no wind is blown onto the plate, thereby influencing its normal traffic signing purpose. PA1 2. If the axis 17 is inferentially arranged to be horizontally posed and no wind is blown, the plate 10 may be inclinedly positioned to influence its normal signing function if no counter weight is added on the plate 10. PA1 3. Even the plate 10 may inferentially reflect any incident light projecting onto the plate for traffic warning or indicating purpose, the optical reflective effect is not so good to reduce its warning or indication function. Nevertheless, the plate 10 may be coated with retroreflective material for increasing its optical reflective property. If by coating two retroreflective sheets on two opposite surfaces of the plate 10, the plate 10, once being rotated, may reflect any incident light, but will not exert a flashing effect since both surfaces can reflect the incoming light rays. PA1 4. Naturally, if only a single surface of the plate 10 is coated with retroreflective material, the other metal surface of the plate may still reflect light, thereby being unable to produce a flashing effect for an increased traffic warning effect.
Caper disclosed a weighted pivoted sign in his Canadian Patent No. 463,479 by incorporating a weighting medium 6 within a horizontal element 4 of the base mmber M mounted on a lower portion of the panel P. Since the panel P and the base member M are not symmetrically disposed on an upper and a lower side of an axis of the trunnions 2, how can it be rotated smoothly and effectively even subjected to a wind pressure acting upon the panel P and the base member M?
The present inventor has found the drawbacks of the conventional displays and signs, and invented the present flashing sign actuated by wind.